MLA

Hughes, Langston, 1902-1967. Walker, Jack. Box 21, folder 319. 1875-1978. https://collections.library.yale.edu/catalog/16207096.

APA, 6th edition

Hughes, Langston, 1902-1967. (["Box 21, folder 319"])(1875-1978)[Walker, Jack]. https://collections.library.yale.edu/catalog/16207096.